Human memory B cells originate from three distinct germinal center-dependent and -independent maturation pathways

Abstract Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27−IgG+ and CD27+IgM+ B cells are derived from primary germinal center reactions, and CD27+IgA+ and CD27+IgG+ B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27−IgA+ memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27−IgA+ cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases.

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Complexity of the human memory B-cell compartment is determined by the versatility of clonal diversification in germinal centers

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1511270112 ◽

2015 ◽

Vol 112 (38) ◽

pp. E5281-E5289 ◽

Cited By ~ 29

Author(s):

Bettina Budeus ◽

Stefanie Schweigle de Reynoso ◽

Martina Przekopowitz ◽

Daniel Hoffmann ◽

Marc Seifert ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Cell Clone ◽

Human Memory ◽

Memory B Cells ◽

Sequencing Analysis ◽

Cell Compartment ◽

Memory B Cell ◽

Cell Clones ◽

B Cell Subsets

Our knowledge about the clonal composition and intraclonal diversity of the human memory B-cell compartment and the relationship between memory B-cell subsets is still limited, although these are central issues for our understanding of adaptive immunity. We performed a deep sequencing analysis of rearranged immunoglobulin (Ig) heavy chain genes from biological replicates, covering more than 100,000 memory B lymphocytes from two healthy adults. We reveal a highly similar B-cell receptor repertoire among the four main human IgM+ and IgG+ memory B-cell subsets. Strikingly, in both donors, 45% of sequences could be assigned to expanded clones, demonstrating that the human memory B-cell compartment is characterized by many, often very large, B-cell clones. Twenty percent of the clones consisted of class switched and IgM+(IgD+) members, a feature that correlated significantly with clone size. Hence, we provide strong evidence that the vast majority of Ig mutated B cells—including IgM+IgD+CD27+ B cells—are post-germinal center (GC) memory B cells. Clone members showed high intraclonal sequence diversity and high intraclonal versatility in Ig class and IgG subclass composition, with particular patterns of memory B-cell clone generation in GC reactions. In conclusion, GC produce amazingly large, complex, and diverse memory B-cell clones, equipping the human immune system with a versatile and highly diverse compartment of IgM+(IgD+) and class-switched memory B cells.

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Optimisation of ex vivo memory B cell expansion/differentiation for interrogation of rare peripheral memory B cell subset responses

Wellcome Open Research ◽

10.12688/wellcomeopenres.11386.2 ◽

2018 ◽

Vol 2 ◽

pp. 97 ◽

Cited By ~ 1

Author(s):

Luke Muir ◽

Paul F. McKay ◽

Velislava N. Petrova ◽

Oleksiy V. Klymenko ◽

Sven Kratochvil ◽

...

Keyword(s):

Cell Culture ◽

B Cells ◽

B Cell ◽

Cell Expansion ◽

Ex Vivo ◽

Cell Subset ◽

Human Memory ◽

Memory B Cells ◽

Memory B Cell ◽

B Cell Subsets

Background:Human memory B cells play a vital role in the long-term protection of the host from pathogenic re-challenge. In recent years the importance of a number of different memory B cell subsets that can be formed in response to vaccination or infection has started to become clear. To study memory B cell responses, cells can be culturedex vivo,allowing for an increase in cell number and activation of these quiescent cells, providing sufficient quantities of each memory subset to enable full investigation of functionality. However, despite numerous papers being published demonstrating bulk memory B cell culture, we could find no literature on optimised conditions for the study of memory B cell subsets, such as IgM+memory B cells.Methods:Following a literature review, we carried out a large screen of memory B cell expansion conditions to identify the combination that induced the highest levels of memory B cell expansion. We subsequently used a novel Design of Experiments approach to finely tune the optimal memory B cell expansion and differentiation conditions for human memory B cell subsets. Finally, we characterised the resultant memory B cell subpopulations by IgH sequencing and flow cytometry.Results:The application of specific optimised conditions induce multiple rounds of memory B cell proliferation equally across Ig isotypes, differentiation of memory B cells to antibody secreting cells, and importantly do not alter the Ig genotype of the stimulated cells. Conclusions:Overall, our data identify a memory B cell culture system that offers a robust platform for investigating the functionality of rare memory B cell subsets to infection and/or vaccination.

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Optimisation of ex vivo memory B cell expansion/differentiation for interrogation of rare peripheral memory B cell subset responses

Wellcome Open Research ◽

10.12688/wellcomeopenres.11386.1 ◽

2017 ◽

Vol 2 ◽

pp. 97 ◽

Cited By ~ 1

Author(s):

Luke Muir ◽

Paul F. McKay ◽

Velislava N. Petrova ◽

Oleksiy V. Klymenko ◽

Sven Kratochvil ◽

...

Keyword(s):

Cell Culture ◽

B Cells ◽

B Cell ◽

Cell Expansion ◽

Ex Vivo ◽

Cell Subset ◽

Human Memory ◽

Memory B Cells ◽

Memory B Cell ◽

B Cell Subsets

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Potential anti-EBV effects associated with elevated interleukin-21 levels: a case report

BMC Infectious Diseases ◽

10.1186/s12879-020-05609-z ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Kristian Assing ◽

Christian Nielsen ◽

Marianne Jakobsen ◽

Charlotte B. Andersen ◽

Kristin Skogstrand ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cells ◽

B Cell ◽

Plasma Cell ◽

Germinal Center ◽

Plasma Cells ◽

Cell Formation ◽

Memory B Cells ◽

Memory B Cell

Abstract Background Germinal center derived memory B cells and plasma cells constitute, in health and during EBV reactivation, the largest functional EBV reservoir. Hence, by reducing germinal center derived formation of memory B cells and plasma cells, EBV loads may be reduced. Animal and in-vitro models have shown that IL-21 can support memory B and plasma cell formation and thereby potentially contribute to EBV persistence. However, IL-21 also displays anti-viral effects, as mice models have shown that CD4+ T cell produced IL-21 is critical for the differentiation, function and survival of anti-viral CD8+ T cells able to contain chronic virus infections. Case presentation We present immunological work-up (flow-cytometry, ELISA and genetics) related to a patient suffering from a condition resembling B cell chronic active EBV infection, albeit with moderately elevated EBV copy numbers. No mutations in genes associated with EBV disease, common variable immunodeficiency or pertaining to the IL-21 signaling pathway (including hypermorphic IL-21 mutations) were found. Increased (> 5-fold increase 7 days post-vaccination) CD4+ T cell produced (p < 0.01) and extracellular IL-21 levels characterized our patient and coexisted with: CD8+ lymphopenia, B lymphopenia, hypogammaglobulinemia, compromised memory B cell differentiation, absent induction of B-cell lymphoma 6 protein (Bcl-6) dependent peripheral follicular helper T cells (pTFH, p = 0.01), reduced frequencies of peripheral CD4+ Bcl-6+ T cells (p = 0.05), compromised plasmablast differentiation (reduced protein vaccine responses (p < 0.001) as well as reduced Treg frequencies. Supporting IL-21 mediated suppression of pTFH formation, pTFH and CD4+ IL-21+ frequencies were strongly inversely correlated, prior to and after vaccination, in the patient and in controls, Spearman’s rho: − 0.86, p < 0.001. Conclusions To the best of our knowledge, this is the first report of elevated CD4+ IL-21+ T cell frequencies in human EBV disease. IL-21 overproduction may, apart from driving T cell mediated anti-EBV responses, disrupt germinal center derived memory B cell and plasma cell formation, and thereby contribute to EBV disease control.

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A role for Toll-like receptors in acquired immunity: up-regulation of TLR9 by BCR triggering in naive B cells and constitutive expression in memory B cells

Blood ◽

10.1182/blood-2002-11-3569 ◽

2003 ◽

Vol 101 (11) ◽

pp. 4500-4504 ◽

Cited By ~ 463

Author(s):

Nadia L. Bernasconi ◽

Nobuyuki Onai ◽

Antonio Lanzavecchia

Keyword(s):

B Cells ◽

B Cell ◽

Constitutive Expression ◽

Human Memory ◽

Cell Receptor ◽

Primary Response ◽

Memory B Cells ◽

Toll Like Receptors ◽

Polyclonal Activation ◽

B Cell Subsets

Abstract Toll-like receptors (TLRs) are pattern recognition receptors that trigger innate immunity. In this study we investigated the expression of 10 TLRs in human naive and memory B-cell subsets. We report that in human naive B cells most TLRs are expressed at low to undetectable levels, but the expression of TLR9 and TLR10 is rapidly induced following B-cell-receptor (BCR) triggering. In contrast, memory B cells express several TLRs at constitutively high levels. The differential expression of TLR9 correlates with responsiveness to its agonist, CpG DNA. Thus, human memory B cells proliferate and differentiate to immunoglobulin (Ig)–secreting cells in response to CpG, while naive B do so only if simultaneously triggered through the BCR. The BCR-induced expression of TLRs in human naive B cells prevents polyclonal activation in a primary response, because it restricts stimulation to antigen-specific B cells. In contrast, the constitutive expression of TLRs in memory B cells allows polyclonal activation of the entire memory pool. Thus, in human B cells TLRs are downstream of BCR and play a role both in the primary response and in the memory phase.

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Multiscale Modeling of Germinal Center Recapitulates the Temporal Transition From Memory B Cells to Plasma Cells Differentiation as Regulated by Antigen Affinity-Based Tfh Cell Help

Frontiers in Immunology ◽

10.3389/fimmu.2020.620716 ◽

2021 ◽

Vol 11 ◽

Author(s):

Elena Merino Tejero ◽

Danial Lashgari ◽

Rodrigo García-Valiente ◽

Xuefeng Gao ◽

Fabien Crauste ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Cell Fate ◽

Plasma Cell ◽

Germinal Center ◽

Plasma Cells ◽

Asymmetric Division ◽

Memory B Cells ◽

Memory B Cell ◽

Germinal Center Reaction

Germinal centers play a key role in the adaptive immune system since they are able to produce memory B cells and plasma cells that produce high affinity antibodies for an effective immune protection. The mechanisms underlying cell-fate decisions are not well understood but asymmetric division of antigen, B-cell receptor affinity, interactions between B-cells and T follicular helper cells (triggering CD40 signaling), and regulatory interactions of transcription factors have all been proposed to play a role. In addition, a temporal switch from memory B-cell to plasma cell differentiation during the germinal center reaction has been shown. To investigate if antigen affinity-based Tfh cell help recapitulates the temporal switch we implemented a multiscale model that integrates cellular interactions with a core gene regulatory network comprising BCL6, IRF4, and BLIMP1. Using this model we show that affinity-based CD40 signaling in combination with asymmetric division of B-cells result in switch from memory B-cell to plasma cell generation during the course of the germinal center reaction. We also show that cell fate division is unlikely to be (solely) based on asymmetric division of Ag but that BLIMP1 is a more important factor. Altogether, our model enables to test the influence of molecular modulations of the CD40 signaling pathway on the production of germinal center output cells.

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Human germinal center B cells express the apoptosis-inducing genes Fas, c-myc, P53, and Bax but not the survival gene bcl-2.

Journal of Experimental Medicine ◽

10.1084/jem.183.3.971 ◽

1996 ◽

Vol 183 (3) ◽

pp. 971-977 ◽

Cited By ~ 156

Author(s):

H Martinez-Valdez ◽

C Guret ◽

O de Bouteiller ◽

I Fugier ◽

J Banchereau ◽

...

Keyword(s):

Cell Cycle ◽

B Cells ◽

B Cell ◽

Germinal Center ◽

Somatic Hypermutation ◽

Cell Subset ◽

Variable Region ◽

Negative Regulator ◽

Memory B Cell ◽

Survival Gene

During T cell-dependent antibody responses, B cells within germinal centers (GC) alter the affinity of their antigen receptor by introducing somatic mutations into variable region of immunoglobulin (IgV) genes. During this process, GC B cells are destined to die unless positively selected by antigens and CD40-ligand. To understand survival/death control of germinal center B cell, the expression of four apoptosis-inducing genes, Fas, c-myc, Bax, and P53, together with the survival gene bcl-2, has been analyzed herein among purified tonsillar naive, GC, and memory B cells. IgD+CD38- naive B cells were separated into CD23- (mature B cell [Bm]1) subset and CD23+ (Bm2), IgD-CD38+ GC B cells were separated into subsets of CD77+ centroblasts (Bm3) and CD77- centrocytes (Bm4), whereas IgD-CD38- cells represented the Bm5 memory B cell subset. Sequence analysis of IgV region genes indicated that somatic hypermutation was triggered in the Bm3 centroblast subset. Here we show that bcl-2 is only detectable with naive (Bm1 and 2) and memory B cell (Bm5) subsets, whereas all four apoptosis-inducing genes were most significantly expressed within GC B cells. Fas was equally expressed in Bm3 centroblasts and Bm4 centrocytes, whereas Bax was most significantly expressed in Bm4 centrocytes. c-myc, a positive regulator of cell cycle, was most significantly expressed in proliferating Bm3 centroblasts, whereas P53, a negative regulator of cell cycle, was most signficantly expressed in nonproliferating Bm4 centrocytes. The present results indicate that the survival/death of GC B cells are regulated by the up- and downregulation of multiple genes, among which the expression of c-myc and P53 in the absence of bcl-2 may prime the proliferating Bm3 centroblasts and nonproliferating Bm4 centrocytes to apoptosis.

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Characterising the Phenotypic Diversity of Antigen-Specific Memory B Cells Before and After Vaccination

Frontiers in Immunology ◽

10.3389/fimmu.2021.738123 ◽

2021 ◽

Vol 12 ◽

Author(s):

M. Christian Tjiam ◽

Sonia Fernandez ◽

Martyn A. French

Keyword(s):

B Cells ◽

B Cell ◽

Phenotypic Diversity ◽

Binding Capacity ◽

Booster Vaccination ◽

Cell Receptor ◽

Memory B Cells ◽

Cell Phenotype ◽

Antigen Binding ◽

B Cell Subsets

The diversity of B cell subsets and their contribution to vaccine-induced immunity in humans are not well elucidated but hold important implications for rational vaccine design. Prior studies demonstrate that B cell subsets distinguished by immunoglobulin (Ig) isotype expression exhibit divergent activation-induced fates. Here, the antigen-specific B cell response to tetanus toxoid (TTd) booster vaccination was examined in healthy adults, using a dual-TTd tetramer staining flow cytometry protocol. Unsupervised analyses of the data revealed that prior to vaccination, IgM-expressing CD27+ B cells accounted for the majority of TTd-binding B cells. 7 days following vaccination, there was an acute expansion of TTd-binding plasmablasts (PB) predominantly expressing IgG, and a minority expressing IgA or IgM. Frequencies of all PB subsets returned to baseline at days 14 and 21. TTd-binding IgG+ and IgA+ memory B cells (MBC) exhibited a steady and delayed maximal expansion compared to PB, peaking in frequencies at day 14. In contrast, the number of TTd-binding IgM+IgD+CD27+ B cells and IgM-only CD27+ B cells remain unchanged following vaccination. To examine TTd-binding capacity of IgG+ MBC and IgM+IgD+CD27+ B cells, surface TTd-tetramer was normalised to expression of the B cell receptor-associated CD79b subunit. CD79b-normalised TTd binding increased in IgG+ MBC, but remained unchanged in IgM+IgD+CD27+ B cells, and correlated with the functional affinity index of plasma TTd-specific IgG antibodies, following vaccination. Finally, frequencies of activated (PD-1+ICOS+) circulating follicular helper T cells (cTFH), particularly of the CXCR3-CCR6- cTFH2 cell phenotype, at their peak expansion, strongly predicted antigen-binding capacity of IgG+ MBC. These data highlight the phenotypic and functional diversity of the B cell memory compartment, in their temporal kinetics, antigen-binding capacities and association with cTFH cells, and are important parameters for consideration in assessing vaccine-induced immune responses.

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EBV Can Induce Somatic Hypermutation in Naïve B Cells In Vitro but Ig Class Switching Requires T Cell Help.

Blood ◽

10.1182/blood.v108.11.2370.2370 ◽

2006 ◽

Vol 108 (11) ◽

pp. 2370-2370

Author(s):

Sridhar Chaganti ◽

Noelia Begue Pastor ◽

Gouri Baldwin ◽

Claire Shannon-Lowe ◽

Regina Feederle ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

Germ Line ◽

Somatic Hypermutation ◽

Memory B Cells ◽

Class Switching ◽

B Cell Subsets ◽

T Cell Help

Abstract Following primary infection, Epstein-Barr virus (EBV) establishes life long persistence in the host IgD− CD27+ memory B cell compartment rather than the IgD+ CD27+ marginal zone (MZ)-like or the IgD+ CD27− naïve B cell compartments. One possible explanation for such exclusive persistence in memory B cells is that EBV preferentially infects memory B cells. Alternatively, the virus may infect all B cell subsets but then drive MZ and naïve B cells to acquire the Ig isotype-switched phenotype and hypermutated Ig genotype of memory cells. Here we ask whether there is any evidence for one or other hypothesis from in vitro experiments. B cells from healthy donor blood samples were FACS sorted on the basis of IgD/CD27 expression into naïve, MZ, and memory B cell subsets with purities of >99%, >97% and >98% respectively. Analysis of the IgVH sequence further confirmed purity of the FACS sorted B cell subsets. Accordingly, 102 of 105 IgVH sequences amplified from purified naïve B cells were germ-line where as the vast majority of sequences amplified from MZ and memory B cells were mutated. All three B cell subsets expressed equal amounts of CD21 (EBV receptor on B cells), bound similar amounts of virus, and transformed with equal efficiency to establish B lymphoblastoid cell lines (LCLs) in vitro. Naïve B cell transformants upregulated CD27 expression but retained the IgM+, IgD+ phenotype as determined by FACS analysis and RT-PCR; MZ-B derived LCLs likewise were IgM+, IgD+, CD27+; and memory-B derived LCLs were consistently CD27+, IgD− and expressed either IgG, IgA or in some cases IgM. Therefore, EBV infection per se did not induce class switching. However, both naïve and MZ-B derived LCLs could still be induced to switch to IgG in the presence of CD40 ligand and IL-4; signals that are normally provided by T cells in vivo. To assess if EBV infection might drive Ig hypermutation, we carried out IgVH sequence analysis on the naïve-B derived LCL clones. Interestingly, 42 of 114 clonal IgVH sequences amplified from naïve-B derived LCLs had 3 or more mutations and the patterns of mutation seen were consistent with that produced by somatic hypermutation (SHM). Furthermore, within some naïve-B cell derived LCL clones, there were both germ-line and mutated sequences all sharing the same VDJ rearrangement (CDR3 sequence), again implying sequence diversification following EBV transformation of a single naïve B cell. Some intraclonal variation of the already hypermutated IgVH sequence was also noted in memory and MZ-B derived LCLs further suggesting ongoing mutational activity. Consistent with this, activation-induced cytidine deaminase (AID) expression was upregulated in transformants as assessed by real time RT-PCR. Our in vitro data is therefore compatible with a model of EBV persistence where the virus infects all mature B cell subsets but then drives infected naïve B cells to acquire a memory genotype by inducing SHM. In addition, EBV infected naïve and MZ-B cells may undergo Ig class switching to acquire the IgD− CD27+ memory phenotype in the presence of T cell help in vivo. EBV’s ability to induce SHM may also contribute to the lymphomagenic potential of the virus in addition to its B cell transforming and growth promoting properties.

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High-Throughput Ig Sequencing of Paired Blood and Spleen Samples Allows a Redefinition of Memory IgM Subsets in Humans

Blood ◽

10.1182/blood.v124.21.565.565 ◽

2014 ◽

Vol 124 (21) ◽

pp. 565-565

Author(s):

Davide Bagnara ◽

Margherita Squillario ◽

David Kipling ◽

Thierry Mora ◽

Aleksandra Walczak ◽

...

Keyword(s):

B Cells ◽

B Cell ◽

High Throughput ◽

Germinal Center ◽

Marginal Zone ◽

Cell Subset ◽

Memory B Cells ◽

Double Negative ◽

Marginal Zone B Cells ◽

B Cell Subsets

Abstract In humans, whether B cells with the IgM+IgD+CD27+ phenotype represent an independent lineage involved in T-independent responses, similar to mouse marginal zone B cells, or whether they are part of the germinal center-derived memory B-cell pool generated during responses to T-dependent antigens, is still a debated issue. To address this question, we performed high-throughput Ig sequencing of B-cell subsets from paired blood and spleen samples and analyzed the clonal relationships between them. We isolated and analyzed 3 different B cell subsets based on CD27 and IgD staining from both blood and spleen: IgD+CD27+ (MZ) - amplified with Cmu primers IgD-CD27+ (switched and IgM-only) with Cmu, Cgamma and Calpha primers IgD-CD27- (CD27- memory or double-negative DN) with the same three primers We obtained 95729 unique sequences that clustered in 49199 different clones: 1125 clones were shared between blood and spleen of the same B-cell subset, and 1681 clones were shared between different subsets, allowing us to trace their relationships. We analyzed these clones that share sequences from different subsets/tissues for their mutation frequency distribution, CDR3-length, and VH/JH family usage, and compared these different characteristics with the bulk of sequences from their respective subset of origin. The analysis of clones shared between blood and spleen for switched IgG/IgA and for MZ subsets suggests different recirculation dynamics. For switched cells, the blood appears to be a mixture of splenic and other lymphoid tissues B cells. For MZ B cells in contrast, the blood appear to be only composed of a subgroup of the splenic repertoire, in agreement with the observation that marginal zone B cells recirculate and are mainly generated in the spleen. Clonal relationships between the IgM clones (originating from the MZ, IgM-only and double negative compartments) show that the clones involved display the characteristics of IgM-only B cells whatever their subset of origin, even in the case of the paired MZ/double-negative sequences that were not supposed to include IgM-only sequences. We therefore conclude that the clones shared between the various IgM subsets do not represent b between them, but rather correspond to a heterogeneous phenotype of the IgM-only population that concerns both IgD and CD27 expression, leading to a partial overlap with the MZ and double-negative gates. Clones shared between the MZ and the switched IgG and IgA compartment also show, for their IgM part, the mutation and repertoire characteristics of IgM-only cells and not of MZ B cells, reinforcing the conclusion that IgM-only are true memory B cells, and constitute the only subset showing clonal relationships with switched memory B cells. In summary, we report that MZ B cells have different recirculation characteristics and do not show real clonal relationships with IgM-only and switched memory B cells, in agreement with the notion that they represent a distinct differentiation pathway. In contrast, the only precursor-product relationship between IgM memory and switched B cells appear to concern a B cell subset that has been described as "IgM-only", but appears to have a more heterogeneous expression of IgD than previously reported and therefore contribute to 3-15% of the MZ compartment. Searching for markers that would permit to discriminate between marginal zone and germinal center-derived IgM memory B cells is obviously required to further delineate their respective function. Disclosures No relevant conflicts of interest to declare.

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